# Question

It has been found that times taken by people to complete a particular tax form follow a normal distribution with a mean of 100 minutes and a standard deviation of 30 minutes. A random sample of nine people who have completed this tax form was taken.
a. What is the probability that the sample mean time taken is more than 120 minutes?
b. The probability is 0.20 that the sample mean time taken is less than how many minutes?
c. The probability is 0.05 that the sample standard deviation of time taken is less than how many minutes?

Sales0
Views41
Comments0
• CreatedJuly 07, 2015
• Files Included
Post your question
5000